Initial impacts of rain gardens＇ application on water quality and quantity in combined sewer： field-scale experiment  

作　　者：Isam Alyaseri Jianpeng Zhou Susan M. Morgan Andrew Bartlett 

机构地区：[1]Department of Civil Engineering, Al-Muthanna University, Alsamawah, Al-Muthanna 72001, Iraq [2]Department of Civil Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026, USA [3]Graduate School, Southern Illinois University Edwardsville, Edwardsville, IL 62026, USA [4]Agricultural Statistics Laboratory, University of Arkansas, Fayetteville, AR 72701, USA

出　　处：《Frontiers of Environmental Science & Engineering》2017年第4期127-138,共12页环境科学与工程前沿（英文）

摘　　要：Green infrastructures such as rain gardens can benetit onsite reduction ot stormwater runott, leading to reduced combined sewer overflows. A pilot project was conducted to evaluate the impact of rain gardens on the water quality and volume reduction of storm runoff from urban streets in a combined sewer area. The study took place in a six-block area on South Grand Boulevard in St. Louis, Missouri. The impact was assessed through a comparison between the pre-construction （2011/2012） and the post-construction （2014） phases. Shortly after the rain gardens were installed, the levels of total suspended solids, chloride, total nitrogen, total phosphorous, zinc, and copper increased. The level of mercury was lower than the detection level in both phases. E. coli was the only parameter that showed statistically significant decrease following the installation of rain gardens. The likely reason for initial increase in monitored water quality parameters is that the post-construction sampling began after the rain gardens were constructed but before planting, resulted from soil erosion and wash-out from the mulch. However, the levels of most of water quality parameters decreased in the following time period during the post-construction phase. The study found 76% volume reduction of stormwater runoff following the installation of rain gardens at one of studied sites. Statistical analysis is essential on collected data because of the encountered high variability of measured flows resulted from low flow conditions in studied sewers.Green infrastructures such as rain gardens can benetit onsite reduction ot stormwater runott, leading to reduced combined sewer overflows. A pilot project was conducted to evaluate the impact of rain gardens on the water quality and volume reduction of storm runoff from urban streets in a combined sewer area. The study took place in a six-block area on South Grand Boulevard in St. Louis, Missouri. The impact was assessed through a comparison between the pre-construction （2011/2012） and the post-construction （2014） phases. Shortly after the rain gardens were installed, the levels of total suspended solids, chloride, total nitrogen, total phosphorous, zinc, and copper increased. The level of mercury was lower than the detection level in both phases. E. coli was the only parameter that showed statistically significant decrease following the installation of rain gardens. The likely reason for initial increase in monitored water quality parameters is that the post-construction sampling began after the rain gardens were constructed but before planting, resulted from soil erosion and wash-out from the mulch. However, the levels of most of water quality parameters decreased in the following time period during the post-construction phase. The study found 76% volume reduction of stormwater runoff following the installation of rain gardens at one of studied sites. Statistical analysis is essential on collected data because of the encountered high variability of measured flows resulted from low flow conditions in studied sewers.

关 键 词：Rain gardens Bioretention Combined sewer Stormwater quality and quantity 

分 类 号：TU991.114[建筑科学—市政工程] X832[环境科学与工程—环境工程]